When Uranium Disintegrates into Lead, One Step in the Process

question 128

Multiple Choice

When uranium disintegrates into lead, one step in the process is the radioactive decay of radium into radon gas. Radon enters through the soil into home basements, where it presents a health hazard if inhaled. In the simplest case of radon detection, a sample of air with volume V is taken. After equilibrium has been established, the radioactive decay D of the radon gas is counted with efficiency E over time t. The radon concentration C present in the sample of air varies directly as the product of D and E and inversely as the product of V and t. For a fixed radon concentration C and time t, find the change in the radioactive decay count D if V is multiplied by 2 and E is reduced by 14%.

• A)increases 255.81%
• B)increases 281.40%
• C)increases 175.44%
• D)increases 232.56%
• E)increases 1,428.57%

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